Study: Eczema may be linked to food allergy development

Scientists have known for a while that eczema and food allergies are linked, but a new study shows the skin condition may actually play a role in the development of allergies.

Children with skin barrier issues, such as eczema, are more than six times more likely to have food allergies than children without the condition, researchers at King’s College London, have found. Eczema affects one in five kids in the U.K. Eczema, or dermatitis, causes skin to become dry and itchy.

Researchers at the college, along with fellow researchers at the University of Dundee, studied data from more than 600 three-month-old babies who participated in the Enquiring About Tolerance (EAT) study. These babies, who were breastfed since birth, had not eaten any solid foods, which downplayed the role of the gut in the development of food allergy. Researchers checked the babies for eczema, checked their skin for water retention and looked for genetic markers of eczema then conducted skin prick tests to look for sensitivities to six of the most common allergenic foods, including egg white, cow’s milk and peanut.

They found that the worst the eczema, the more sensitive the children were to the allergenic foods (although it didn’t always develop into a full allergy). The findings highlight the role the skin may play in the development of food allergies – that is, a breakdown in the skin because of eczema (or other skin issues) exposes immune cells to environmental allergens, which can cause an allergic response.

“This is a very exciting study, providing further evidence that an impaired skin barrier and eczema could play a key role in triggering food sensitivity in babies, which could ultimately lead to the development of food allergies,” said Dr. Carsten Flohr, NIHR clinician scientist and senior lecturer at King’s College London and consultant at St John’s Institute of Dermatology at St. Thomas’ Hospital, in a statement. “This work takes what we thought we knew about eczema and food allergy and flips it on its head – we thought that food allergies are triggered from the inside out, but our work shows that in some children it could be from the outside in, via the skin. The skin barrier plays a crucial role in protecting us from allergens in our environment, and we can see here that when that barrier is compromised, especially in eczema, it seems to leave the skin’s immune cells exposed to these allergens. It opens up the possibility that if we can repair the skin barrier and prevent eczema effectively then we might also be able to reduce the risk of food allergies.”

Although almost any food can be allergenic, 90 percent of food allergic reactions are caused by only eight foods: peanuts, eggs, milk, tree nuts, wheat, fish, soy and shellfish. An allergic reaction is an immune response. Symptoms of food allergic reactions can range from mild, such as hives, to severe including throat swelling, difficulty breathing and anaphylactic shock.